How can I undo changes to unstaged files?

Suppose you have made changes to a file, then decide you want to undo them. Your text editor may be able to do this, but a more reliable way is to let Git do the work. The command:

git checkout -- filename

will discard the changes that have not yet been staged. (The double dash -- must be there to separate the git checkout command from the names of the file or files you want to recover.)

Use this command carefully: once you discard changes in this way, they are gone forever.

You are in the dental repository, where all changes to .csv files in data were staged. git status shows that data/northern.csv was changed again after it was staged. Use a Git command to undo the changes to the file data/northern.csv.

Exercise

How can I undo changes to unstaged files?

Instructions